Drs Jaroslav Dudik, Giulio Del Zanna and Helen Mason of DAMTP and their collaborators have reported in a paper in Astrophysical Journal new observations of an enormous solar flare. Detailed analysis of the observations shows convincing agreement with recent state-of-the-art numerical simulations, thereby building confidence in the model used for those simulations. The magnetic disturbance associated with such flares can potentially cause major disruption to communications networks and better predictive capability is therefore a major priority.